Zeno was reputedly inspired to study philosophy after reading the second book of Xenophon’s Memorablia of Socrates. This actually begins with a chapter in which Socrates recounts a story known as “The Choice of Hercules” (or “Heracles” to the Greeks), attributed to the highly-regarded ancient sophist Prodicus (Memorabilia, 2.1). Antisthenes, the Cynics, and the Stoics apparently all agreed that Hercules, the greatest of Zeus’ sons, provided an ideal example of the self-discipline and endurance required to be a true philosopher. The story symbolises the great challenge of deciding whom we actually want to be in life, what type of life we want to live, the promise of philosophy, and the temptation of vice. Zeno himself was perhaps compared to Hercules by his followers and we know that his successor Cleanthes was dubbed “a second Hercules”, on account of his self-mastery.

The story goes that Hercules, when a young man, found himself at an isolated fork in the road, where he sat to contemplate his future. Uncertain which path to take in life he found himself confronted by two goddesses. One, a very beautiful and alluring woman, was called Kakia, although she claimed that her friends call her “Happiness” (Eudaimonia). She charged in front to ensure she spoke first, promising him that her path was “easiest and pleasantest”, and that it provided a short-cut to “Happiness”. She claimed he would avoid hardship and enjoy luxury beyond most men’s wildest dreams, produced by the labour of others. After hearing this, Hercules was approached by the second goddess, called Aretê, a plain-dressed and humble woman, though naturally beautiful. To his surprise, she told him that her path would require hard work from him and it would be “long and difficult”. In fact the path Hercules chose would be dangerous beyond belief, he would be tested by many hardships, perhaps more than any man who had lived before, and have to endure great loss and suffering along the way. “Nothing that is really good and admirable”, said Aretê, “is granted by the gods to men without some effort and application.” However, Hercules would have the opportunity to face each adversity with courage and self-discipline, and of showing wisdom and justice despite great danger. He would earn true Happiness by reflecting on his own praiseworthy and honourable deeds.

Hercules, of course, chose the path of Aretê or “Virtue” and was not seduced by Kakia or “Vice”. He faced continual persecution, from the goddess Hera and her minions, and was forced to undertake the legendary Twelve Labours, including slaying the Hydra and ultimately entering Hades, the Underworld itself, to capture Cerberus with his bare hands. He died in the most extreme agony, poisoned by clothing soaked in the Hydra’s blood. However, Zeus was so impressed by his greatness of soul that he elevated him to the status of a God in his own right. Of course, the Stoics took this all as a kind of metaphor for the good life: that it’s better to face hardships, rise above them, and thereby excel, than to embrace easy-living and idleness, and allow your soul to shrink and deteriorate as a result. It would therefore make sense if Socrates retelling of “The Choice of Hercules” was indeed the part of the Memorabilia that inspired Zeno’s conversion to the life of a philosopher. However, it may certainly have served this purpose for later generations of Stoics.